Thousands of iPhone users on the O2 network have been unable to use their
smart phones properly, after the mobile phone operator's network crashed for
almost 48 hours.

Some users have been unable to access the internet on their AppleiPhone, making many of the popular applications – which allow customers to shop, check train times or catch up on the news – redundant.

O2 users have once again vented their frustration on Twitter

Users trying to access applications or the internet were met with the message: "Could not activate cellular data network."

O2 would not say how many of its customers have been affected, but it is understood a large chunk of its more than a million users have been having a problem since Saturday.

On Sunday O2 promised that normal service would be resumed by the end of the day, but by early afternoon on Monday the network was still experiencing problems.

A spokesman for O2 said: "We are aware of an issue currently impacting data access for some of our customers. We have identified a fault with the allocation of IP addresses and are working to resolve this as quickly as possible. We apologise to any affected customers."

People signing up to Vodafone's £40 per month, 18-month contract also have to pay £89 for the iPhone itself, meaning they will have spent £809 on the phone and monthly payments by the time their 18-month contract expires.

This compares with £713.82 on a similar deal with O2 and £712.98 with Orange.